The present invention relates generally to fluid management systems and, more particularly, to an endoscopic distention fluid management assembly, having a vented outlet line, for use in an endoscopic procedure.
Systems for distending and irrigating a surgical site during a surgical procedure, e.g., during a procedure to remove diseased tissue in the uterus, knee, shoulder, bladder and the like are well known in the art. A typical irrigation system includes a source of biocompatible fluid, e.g., a feed bag, tubing which delivers the fluid to the surgical site, and a pump which pumps fluid from the fluid source into the surgical site. The purpose of the irrigation system, at least in part, is to distend the operative space within the uterus, knee, shoulder, bladder, and the like, so that the clinician can clearly identify the anatomy and subsequently remove diseased tissue. A means for aspirating the fluid is typically also provided to remove fluid from the operative space, to flush out loose debris in order to maintain visibility of the surgical site for example, when the fluid becomes somewhat opaque and hard to see through. This type of system forms a part of an overall fluid management system or assembly which controls the flow of fluid.
Different surgical procedures require different irrigation parameters, e.g., fluid pressure and flow rate. Therefore, there are known irrigation systems in which the pressure and/or flow-rate of the irrigation fluid are controlled or varied to accommodate different surgical procedures. For example, U.S. Pat. No. 5,460,490 to Carr et al. describes an irrigation system which can be operated in a plurality of modes for different endoscopic surgical procedures, such as laparoscopic, arthroscopic or hysteroscopic procedures, the disclosure of which is hereby expressly incorporated by reference.
Typical aspiration systems include a suction canister which is attached to an outlet tube. The suction canister is operative to create a negative pressure in the outlet tube to remove fluid from the surgical site. In addition, such systems can be typically operated in a gravity flow mode, in which the fluid is aspirated under gravity and is simply collected and stored by the suction canister.
Such an arrangement can result in some negative performance characteristics. For example, in a gravity flow mode the fluid flows through a vertical length of tubing, which creates a siphon effect and therefore a negative pressure within the tube, which acts to reduce the positive pressure in the operative space, thereby reducing the amount of distention. Moreover, when suction is applied through the outlet tube, high levels of suction may be applied to the operative space, thereby also resulting in an unwanted reduction in the degree of distention within the operative space. This is an undesirable condition and can lead to operative complications.
Over the duration of the surgical procedure, an individual, such as a nurse, measures the amount of fluid being delivered to the patient and the amount of fluid which is recovered from the patient during the procedure. If the amount of fluid being recovered from the patient is less than the amount of fluid being delivered to the patient, a fluid deficit results. A fluid deficit may result due to any number of reasons including but not limited to the occurrence of fluid loss which results from leakage through a cervical seal as well as fluid loss through an outflow port of the endoscope. Since fluid monitoring is a very important part of managing the patient during the operative procedure, all fluids exiting the operative space (i.e., an organ or joint capsule) must be balanced with the fluids entering the operative space so as to maintain an account of the occurrence of any fluid deficit during the procedure. In addition, it is important to monitor whether a fluid imbalance occurs as a result of the patient absorbing an excessive quantity of fluid. If a patient absorbs an excessive quantity of fluid, complications can result including those of a serious nature. Therefore, it is important to continuously monitor the fluids in the operative space during the operative procedure to ensure that the uterus is properly distended to permit sufficient visualization thereof and to ensure that the patient""s safety is maintained.
Typically, the clinician will use a fluid collection system as the surgical procedure is being performed so that fluid may be recovered and collected from the operative site. The endoscope contains an outflow port in which fluid is transferred from the operative site to a remote location where it is collected in a receptacle, such as the suction canister, and then measured to ascertain the total fluid loss of the patient during the procedure. During the procedure, a pouch drape or the like is typically used and is disposed underneath the patient. This drape is designed to collect any fluid which may be discharged from the patient during the procedure. The fluid is caught in the pouch portion and is collected therein for delivery to the remote collection receptacle (the suction canister). The drape and more specifically the pouch portion thereof is also likewise connected to the collection receptacle by means of a fluid carrying device such as attachable tubing which permits the fluid to be effectively transferred to the collection receptacle.
Now referring to FIG. 1 which illustrates a conventional fluid management assembly, generally designated at 10. The collection system 10 comprises a first fluid carrying member 12 which is connected at a first end 14 to a first connector 16 which is designed to engagingly mate with the outflow port of an endoscope (not shown). A second end 17 of the first fluid carrying member 12 is connected to a Y-connector 18 and more specifically is connected to a first leg 20 thereof. The management assembly 10 further includes a second fluid carrying member 22 which is coupled to a pouch drape (not shown) at a first end 24 thereof. The first end 24 preferably has a second connector 26 coupled thereto which is designed to permit attachment of the second fluid carrying member 22 to the pouch drape. A second end 28 of the second fluid carrying member 22 is connected to a second leg 30 of the Y-connector 18 with the first and second legs 20, 30 being in parallel orientation relative to one another.
The Y-connector 18 also includes a main leg 32 which extends in an opposite direction relative to the first and second legs 20, 30. The main leg 32 receives and is coupled to a main fluid carrying member 34 which receives fluid from both the first and second fluid carrying members 12, 22 and directs the fluid to a suction source (not shown). It will be appreciated that the suction source serves to supply a sufficient suction force so that the fluid is drawn through all the members 12, 22, 34 and is delivered to the collection receptacle (the suction source). Preferably, the first, second, and third fluid carrying members 12, 22, 34, respectively, comprise tubing which is suitable for use in the intended medical procedures described herein. At the end of the procedure, the total volume of the fluid collected in the collection receptacle is reconciled with the total input volume and a fluid deficit, if any, is calculated for the patient.
The management assembly 10 also preferably includes a pinch clamp 36 which is disposed about the first fluid carrying member 12 and is designed to selectively restrict the flow rate of fluid through the first carrying member 12. The illustrated pinch clamp 36 includes a ratchet mechanism which is designed to pinch the first fluid carrying member 12 between a pair of protuberances, generally indicated at 38. As the pinch clamp 36 is manipulated so that the first fluid carrying member 12 is further constricted between the protuberances 38, the flow rate of the fluid decreases.
The management assembly 10 also preferably further includes a flow restrictor (not shown) which is coupled to the first end 24 of the second fluid carrying member 22. The pouch drape does not always contain fluid and when this condition exists, the Y-connector 18 is vented to atmosphere which reduces the suction applied to the endoscope line (the first fluid carrying member 12). By being inserted into the second fluid carrying member 22, the flow restrictor 39 is designed to enhance the suction in the endoscope line so that the fluid is properly drawn from the endoscope whether or not fluid is present in the drape.
While suitable for its intended purpose, the above-described conventional management assembly 10 has associated disadvantages which results in reduced distention at the operative site. Because distention is dependent upon on both inflow and outflow performance, optimization of the fluid inflow and outflow will result in distention being likewise optimized. During distention of the operative space, fluid is pumped into the operative space to develop positive pressure, which is required in order to increase the volume of the operative space. The fluid pumped into the uterine space is delivered by means of the endoscope which has an inflow port along with the aforementioned outflow port. Fluid which enters the operative space through the inflow port is then relieved through the outflow port. When the fluid is relieved through the outflow port, it is permitted to flow under gravity into the pouch drape for subsequent aspiration into the collection receptacle.
During gravity flow from the outflow port, the fluid flows through a vertical length of the first fluid carrying member 12 which creates the siphon effect previously-mentioned. The magnitude of the siphon effect will depend upon the length of the first fluid carrying member 12 which hangs vertically below the patient. This siphon effect acts as a negative pressure source which serves to reduce the positive pressure acting within the operative space and hence, reduces the amount of distention. This reduction in distention, if significant enough, can slow down the surgical procedure and result in an increase in bleeding which in turn results in impaired visualization of the anatomy.
In addition, the Y-connector 18, as previously described, serves to receive both the fluids from the first and second fluid carrying members 12, 22 under suction so that all of the patient""s fluids may be pooled into one collection canister (the collection receptacle). Using a Y-connector arrangement can result in a decrease in performance since the system flow needs to be mechanically balanced to allow adequate simultaneous entrainment from both the first and second legs 20, 30 of the Y-connector 18. If the first and second legs 20, 30 are not balanced, flow may be biased to one of the first and second legs 20, 30 because the fluid seals the leg with less resistance causing a sumping action to occur. The occurrence of a sumping action results in cycling of pressures at the operative site, bleeding and increases surgical procedure time. For example, when there is a fluid build-up in the pouch drape, the drape acts as a reservoir creating a column of fluid in the second fluid carrying member 22. Because of the column of fluid, the pressure in the second fluid carrying member 22 is increased and this may create a fluid seal which limits the fluid flow through the first fluid carrying member 12 (endoscope line). This causes a recycling of the pressure at the operative site which is undesirable.
Accordingly, it will be apparent to those skilled in the art that there continues to be a need for an improved fluid management system for use in various surgical procedures. The present invention addresses that need.
In one aspect of the present invention, a fluid management assembly for use in an endoscopic procedure is provided. The assembly comprises a first line defining a passage for the flow of fluid with the first line having a first end for connection to an endoscope and an opposing second end. A second line defining a passage for the flow of fluid is also provided with the second line having a first end for connection to a drape and an opposing second end. The assembly further includes a Y-connector having first and second legs in fluid communication with the second ends of the first and second lines. A third line is coupled at a first end to a third leg of the Y-connector and the third line has a second end for connection to a suction source. The third line has a predetermined length such that the Y-connector is positioned in close proximate relation to the suction source, wherein the length of the third line is less than the length of the first and second lines.
The assembly also includes an atmospheric vent disposed within the first line for introducing atmospheric pressure into the first line to relieve any excessive negative pressure build-up within the first line. The atmospheric vent causes a reduction in the negative pressure within the first line when it is open by introducing atmospheric pressure into the first line. Depending upon the embodiment, the atmospheric vent may be either biased open so that the it closes only when a positive pressure build-up is observed in the first line or it may be normally biased closed so that it opens when a set point (pressure value) of the vent is exceeded.
In another aspect of the present invention, a system is provided which includes an outlet tube that leads to a suction canister or other suitable receptacle for collecting fluid. The outlet tube includes an anti-siphon adapter which defines an atmospheric vent downstream of an endoscope or other similar surgical device. The vent allows atmospheric pressure to enter the outflow tube to increase the pressure at the outflow of the endoscope, thereby substantially preventing a siphoning effect from occurring within the outlet tube.